UPDATE: I have actually now gone through it all once more: As before I started with an old, non-Thinkpad Win7 Pro installation DVD, this time only Security > Virtualization -> Intel VT-d Feature: Disabled (even though Win7 has no problem with that) and the Start settings as below. I suspect you can go from any Win7 installation you currently have. Then I installed the 64bit version of the Ethernet driver (http://support.lenovo.com/de/de/downloads/ds019204) as I had to go online to activate it. Since it wasn't a Thinkpad-Win7 install CD I also had to go through activation via phone (that automated service). I didn't install any updates. Then I used the USB stick with the Win10 installer from within Win7 to upgrade (I didn't permit that to download updates either) and it ran through no trouble. So now I'm sure pretty sure my issues were down to the VT-d feature. Even though I'm using VMs I get the impression (from this: http://forum.notebookreview.com/threads ... me.586900/) that I won't need VT-d at all. On to what I had previously written...aharown15 wrote: How did you manage to get Win10 on to a w520? I've tried no less than 9 times w/o success.
So far I haven't found a step by step that works.
(My efforts to date have included returning the unit to factory condition and downloading all "important" Win 7 updates... and most of the 'recommended' ones. Updating all drivers using Lenovo System Update.... and then various mixes of bios settings, none of which worked.)
The error I always come back to is 0xc1900101 - 0x20017 "The installation failed in the safe_os phase with an error during boot operation"
Sure would love to get past that.
Yeah, how to install Windows 10 on the Thinkpad W520? I've struggled a lot with this, too. I tried the various common and less common suggestions such as running chkdsk, removing the DVD drive, updating everything to the latest version and doing the opposite, i.e. just installing Win7 fresh without any updates and I usually ended up with the Win10 installer booting to the Windows logo and then showing between 0 and 2 of those white points that are meant to indicate progress, then it stalled and when I rebooted hours later into Win7 it showed installation failed with same error that you quote (0xc1900101 - 0x20017). In the end I followed Sven Seiler's instructions here: https://seiler.it/windows-10-upgrade-t420s/ and although that's for the T420s it worked for my W520 as well. Don't miss out on the comments underneath the blog post as well for further info.
In case that link ever becomes unavailable, and since it's not apparently on archive.org and I had trouble adding it there, I'll summarise: It's the BIOS settings copied at the bottom of this post (all of which except for Core Multi-Processing he says you can switch back on later) that got me there. It's likely not all of those are needed, but that's what I've tried successfully. Might be worth trying to only disable Core Multi-Processing in the BIOS and seeing if that works, then reporting back here if anyone can be bothered. [Well, in my case it turned out to be the VT-d feature not the Core Multi-Processing that caused trouble.]
Just to give a bit more detail on my particular setup: I've got a W520 (Type: 4276-CTO) with an i7-2720QM, 24 GB RAM, a 1 TB mSATA SSD drive with Win7 Pro and a 1 TB HDD for data. I had taken out the DVD drive while I was trying to upgrade to Win10 since others had reported issues with it being present. Since I failed miserably upgrading, I eventually followed some advice on trying from a fresh Win7 Pro install without any updates and only the Ethernet driver copied over to allow the Win10 installer to get updates. That didn't do the trick either and then I came across Sven's post. I suspect it would have worked just as well on my previous Win7 Pro install but I'm certainly not going to test having wasted far too much time on this already. I suspect it would have worked with the DVD drive in as well. Oh, and I used the W10 installer from a USB stick but again it presumably would have worked with the direct download, too.
So here are the settings from Sven's blog post. Good luck, everyone!
EDIT: After the upgrade I ran Windows Update until it reported no further updates being available. Then I switched everything back on selectively in BIOS (even Core Multi-Processing) and restarted after every change. The only setting that seems to cause trouble for me is "Intel VT-d Feature". When I have that enabled, I get the Windows logo on boot and a couple of points intending to show progress, then it stalls completely. Reliably so, on every restart. Which is exactly what I had when the upgrade from Win7 to Win10 failed for me. So perhaps for the W520 that's the (and perhaps the only) crucial setting that needs to be switched to disabled for the upgrade to work. [I think that's confirmed now, see the UPDATE above, though the BIOS "Start" settings may also be relevant.]
Config > Display
Boot Display Device: Thinkpad LCD
Graphics Device: Discrete Graphics
OS Detection for NVIDIA Optimus: Disabled
Config > Power
Intel Speedstep technology: Disabled
CPU Power Management: Disabled
PCI Express Power Management: Disabled
Config > CPU
Core Multi-Processing: Disabled
Intel Hyper-Threading Technology: Disabled
Security > Memory Protection
Execution Prevention: Disabled
Security > Virtualization
Intel Virtualization Technology: Disabled
Intel VT-d Feature: Disabled
Security > I/O Port Access
All to disabled, expect of Ethernet LAN and eSATA Port to update the Windows installation software before the update
Startup
UEFI/Legacy Boot: Both
UEFI/Legacy Boot Priority: UEFI First
Reserve memory for UEFI Boot Manager: Enabled






